This invention relates generally to a rail gauging apparatus mounted on a vehicle adapted for movements along the rails of a track, and more particularly to such an apparatus which has a vertically movable frame on which rail gauge bars are mounted for accurately gauging the track as rail gauge levers on the frame engage the rails together with the bars. And, a pre-gauger is mounted on the front end of the vehicle for roughly gauging the rails.
Track gaugers of different varieties have been in use for a number of years, many of which are manually operated, and some of which comprise flanged rollers or the like mounted at the front end of a rail vehicle. Such gaugers normally engage the rail heads, and others have been developed for engaging the rail webs for shifting one or both rails during a rail laying or rail renewing operation. The principle drawback to the use of these gaugers is their inherent gauging inaccuracy, not to mention the obvious disadvantages in utilizing manual gaugers. By engaging the rail heads or webs, the rails oftentimes tend to topple instead of being shifted at their base to the necessary extent. This leads to gauging inaccuracy which presents special problems at track elevations and track curves and especially at track curved elevations.
In U.S. Pat. No. 3,552,320, a track gauger utilized with a spike driving device engages the rail base during a rail gauging operation. The gauger is mounted on a rail vehicle and includes rail engaging blade pairs. The blades of each pair are pivotally mounted on a common axes and are interconnected via a linkage arrangement. One of the blades is pivoted by a hydraulic cylinder unit, and its associated blade is pivoted via the linkage arrangement. Clamping blocks at the ends of the blades of one of the blade pairs engage a free or loose rail while the clamping blocks on the blades of the other pair engage a fixed rail, whereupon the loose rail may be shifted relative to the fixed rail to the proper gauge. However, because of the rather complex linkage arrangement between the blades at each pair, accurate rail gauging is difficult to achieve. Worn linkage elements require constant adjustment after even short periods of use, and the operational speed of the gauger is limited. These and other disadvantages are avoided by the present invention which constitutes an improvement over this known rail base gauger.